Flue gas desulphurization (FGD) gypsum is understood as being the hydrated calcium sulphate (CaSO4 • 2 H2O) produced within the flue gas desulphurization of power stations.

In the following, FGD gypsum is also referred to as raw gypsum.

The analysis of FGD gypsum includes the chemical analysis of FGD gypsum constituents and the determination of further properties, which are defined in the quality requirements for gypsum as worked out by Bundesverband der Gipsindustrie as well as by Eurogypsum, VGB PowerTech and ECOBA. It has to be pointed out that raw gypsum from different sampling points may lead to deviating analysis results. The sampling points as well as the extent of the analysis have to be co-ordinated between gypsum producers and customers.

The analytical methods described in Part I are applicable to reference analyses. Other methods can be used for continuous quality control purposes; they are  described in Part II, Analytical Methods - Annex. Newer and/or more efficient methods can be used as well, provided equivalent results are achieved or the results only differ in a constant correlation factor. However, in this case a-yield coordination between the laboratories of the power station (supplier) and the FGD gypsum processor  (purchaser) is recommended.

The quality of the FGD gypsum should allow the production of products which are equivalent to those made of natural gypsum. The actual quality requirements are  defined in the common utilization concept of the gypsum processing and power production industries or in regulations to be agreed upon for each individual case.
Part III contains tables with chemical/physical data for the analysis of gypsum.

(2008)